Optical transceivers are used to transmit and receive optical signals for various applications including, without limitation, internet data center, cable TV broadband, and fiber to the home (FTTH) applications. Optical transceivers provide higher speeds and bandwidth over longer distances, for example, as compared to transmission over copper cables. The desire to provide higher speeds in smaller optical transceiver modules for a lower cost has presented challenges, for example, with respect to thermal management, insertion loss, and manufacturing yield. As the size of the optical transceiver module and its components decreases, manufacturing tolerances typically become more difficult to achieve.
Optical transceiver modules generally include one or more laser packages for housing a laser or laser diode and for providing electrical connections and optical couplings to the laser. An optical coupling path, between the laser and the optical fiber, may generally include a lens to focus the laser light and an optical isolator element to prevent back reflection of the laser light. One challenge with optical transceiver module assembly is the process of bonding the optical fiber to the laser package with a relatively high degree of precision to reduce signal losses that may result from misalignment or other coupling problems. The optical isolator may increase these difficulties by inducing spatial shifts in the laser light. Although these shifts may be relatively small, their effects can become more significant as transceiver modules undergo further miniaturization.